On July 3, the citizens of Thailand resoundingly chose Yingluck Shinawatra to serve as the nation's next prime minister, and its first female leader. Her election was a triumph for populism and democracy, and may stabilize the country's tumultuous political landscape. But to secure Thailand's fate, Yingluck will have to distance herself from her brother: Ex-Prime Minister Thaksin Shinawatra, one of the most controversial men in international politics.

Thaksin, depending on whom you ask, is either Thailand's greatest villain or its savior. A wealthy businessman who was elected in 2001, Thaksin proved himself to be that rarest of politicians: the billionaire deeply concerned with the well-being of the rural poor. He implemented universal healthcare, gave cheap loans to farmers, and invested in community development projects. These policies, termed "Thaksinomics," permanently endeared him to Thailand's agrarian lower classes.

But Thaksin was not only helping the poor during his term, he was also lining his own pockets. In 2006, Thaksin sold Shin Satellite Corp., a telecommunications company that he owned, to a Singapore bank at a nearly $2 billion tax-free profit, just after he had established national policies that enhanced his company's value and eased the sale. In response to this and Thaksin's other conflicts of interest, the Thai military staged a bloodless coup later that year, forcing Thaksin out of power and into exile, where he remains today.

Yet, despite Thaksin's illegal activities, he retains overwhelming support – in 2010, when the acting Thai government seized the ill-gotten $2 billion, thousands of protestors, termed "Red Shirts," held Bangkok hostage. Clearly Thaksin inspires devotion amongst poverty-stricken farmers. They abandoned their farms, traveled hundreds of miles, and lost their lives when the protests turned violent because they were upset that their billionaire leader had some money confiscated.

It is no surprise, then, that last week's election was considered as much a referendum on Thaksin as it was on his sister, Yingluck. The victorious Pheu Thai Party's policies pick up where Thaksin's left off: Free education, a minimum wage increase, and guaranteed income for farmers. This close adherence to Thaksin's political strategy has led many to wonder whether new Prime Minister Yingluck Shinawatra is merely her brother's mouthpiece.

Thaksin certainly thinks so, as he recently referred to Yingluck as his "clone." Yingluck is also the former president of Shin Corp., the telecom company whose shady dealings got her brother into trouble. And most tellingly, one of the Pheu Thai Party's most prominent campaign slogans was the ominous "Thaksin thinks and Pheu Thai does." All those signs point to Yingluck being a proxy for her absentee sibling. And, although Yingluck now denies it, many think that Pheu Thai has considered granting Thaksin amnesty, allowing him to return from exile.

For the sake of Thailand's tenuous political stability, Thaksin cannot be permitted to return. He is too polarizing a figure - while his “Red Shirt” admirers would literally lay down their lives for him, his enemies loathe him just as intensely. And those enemies include some powerful people: Thailand's wealthiest classes, the still-powerful Democratic Party, and the military, which overthrew him in 2006. While the military has claimed that it will not interfere with Yingluck's administration that could certainly change if Thaksin became involved in the country's governance again.

Recent Thai politics have been fraught with election fraud, coups, and near civil war, and Thaksin has fomented the unrest. Thailand took a step away from the tumult and toward a stable democracy with this latest election; however, allowing Thaksin to participate in politics would only revive the chaos. Furthermore, Thailand faces serious financial and social problems, ones that will require cooperation between Yingluck and the now-minority Democratic Party. Yingluck is charismatic enough to forge such partnerships; but, with Thaksin involved, forming coalitions across party lines would be nearly impossible.

Thaksin's reign brought about many positive developments in Thailand, and Yingluck would do well to emulate many of her brother's progressive policies. But she must implement Thaksin's agenda while keeping Thaksin himself at a distance. Allowing him to participate in the government, or even to reenter Thailand at this juncture, would only destabilize a still-volatile situation.